Before becoming a Principal Research Scientist at the University of Alabama in Huntsville in 2001, Roy was a senior scientist for Climate Studies at NASA’s Marshall Space Flight Center, where he and John Christy received NASA’s Exceptional Scientific Achievement Medal for their global temperature monitoring work with satellites. Roy is the United States’ Science Team leader for the Advanced Microwave Scanning Radiometer flying on NASA’s Aqua satellite. Roy received his PhD in meteorology at the University of Wisconsin–Madison in 1981.